The light-sensitive photographic material field requires a silver halide light-sensitive color photographic material which has satisfactory photographic characteristics, which is capable of being processed rapidly, and which enables to obtain high-contrast gradation-having images.
For example, as regards the rapid processing, although silver halide photographic materials were conventionally subjected to the running processing by the automatic processors installed in the individual photofinishers' laboratories, as a part of improving the processing service to users. those photographic materials accepted for processing has been required to be processed to be returned to the users within the day of the accepted date, and besides, even faster return of them; as fast as within several hours after the acceptance, has lately been needed, and thus the development of silver halide color photographic materials that can be processed even more rapidly are urgently needed.
It is known that the use of a silver chloride emulsion is useful as technical means for obtaining such rapidly processable silver halide color photographic materials.
However, the emulsion of silver chloride or of a high silver chloride content, although it can be rapidly processed, is disadvantageous because of its high fog.
On the other hand, attempts are made to obtain a light-sensitive material having its photographic characteristics improved by the addition of a heterocyclic mercapto compound or tetrazaindene compound at the time of preparing its silver halide grains.
Such the prior art will be briefed below:
The processes for preparaing silver halide grains are generically called `physical ripening`, which are comprised of the processes of producing grains, growing the grains, and desalting and redispersiing the grains, or of the processes of growing grains in advance produced, and desalting and redispersing the grains. It is known for long that, in such the preparation of silver halide grains, a compound known as a restrainer to those in the art is added to silver halide at the time of the growth of its grains. However, the prior art that a restrainer is added at the time of the formation of high-silver-chloride-content silver halide grains is used only for changing the crystal habit of the grains as seen in, for example, `The Journal of Photographic Science` Vol.21, p.39 (1973).
Naturally, the above prior art suggests nothing about the prevention of fog, so that it describes no measures therefor.
On the other hand, as regards the color preservability, there are known techniques to use a high-boiling organic solvent at the time of the coupler dissolution in order to increase the fastness of the dye image produced in the color developing system. The technique will then be described: A silver halide photographic material is imagewise exposed and then color-developed, whereby a dye image is formed, but the obtained dye image is desired to have a high fastness against light, heat and moisture. The fastness of the dye image is subject to various factors, and particularly the dye image is knwon to be dependent largely upon the natures of a dye-forming coupler that forms a dye in its reaction with a color developing agent and of a high-boiling organic solvent for use in dissolving the dye-forming coupler. In the selection of a dye-forming coupler, however, although the fastness of the resulting dye is of course important, it is essential for the coupler to form a dye having a satisfactory absorption characteristic for color reproduction, and further it is desirable for the coupler to have a high color-forming efficiency and a high stability in the solvent used, so that the selectable range of a dye-forming coupler has its limit. For this reason, there is a limit to the improvement of the fastness by the selection of a dye-forming coupler. On the other hand, the high-boiling solvent for use in dissolving the dye-forming coupler also has an important effect upon the fastness of the resulting dye therefrom; Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 205447/1985 discloses the improvement on the fastness of dye-forming couplers by use of a specific dielectric constant-having high-boiling solvent.
However, in a light-sensitive material which uses the above publication-disclosed high-boiling organic solvent, the image formed by the dye-forming coupler dissolved by the solvent, although improved on its fastness, shows its gradation is lowered, and its fog also comes into question.
That is, in order to develop a silver halide light-sensitive material adaptable to rapid processing and excellent in the dye image preservability, we used a high-boiling solvent that is described in Japanese Patent O.P.I. Publication No. 205447/1985 in mere combination with the foregoing high-silver chloride-content silver halide. As a result, it has now been found that the resulting dye image, although excellent in its preservability, has the problem that its gradation in the non-aged characteristics is soft and its fog is increased.
As has been described above, a technique is now desired which makes possible to obtain a silver halide color photographic material which produces little or no fog, which is excellent in the image fastness as well as in the color preservability, and of which the gradation of the image formed by the coupler is high-contrast, on condition that the light-sensitive material can be processed much faster than ever.